Hi!
You seem to be having changes specific to brain injury and even probably spinal nerve compression in the neck region. Nausea, vomiting, excess sleep, severe headache, difficulty in walking and balance, tremors, seizures, vision problems, ringing in ears etc are all signs of head injury. You need to get this investigated immediately. Please go to the ER and get a complete neurological examination along with MRI of head and neck region. Take care!